Evaluation of bOpto-BMP/Nodal Expressing Embryos After the Light Exposure Experiment

For the phenotyping assay, perform the light exposure experiment on bOpto-BMP bOpto-Nodal expressing zebrafish embryos, and remove them from the light box at one day post-fertilization between 24 to 32 HPF. Using a dissecting scope, evaluate phenotypes and establish a scoring rubric. Assess embryos while they remain within the chorion for convenience.

Utilize a pipette to probe to reposition embryos for viewing from different angles. For the immunofluorescence assay, after incubating embryos in 4%formaldehyde at four degrees Celsius overnight, remove the formaldehyde and rinse them three to five times with PBST. Discard the PBST and add 100%methanol.

Seal the tubes and gently invert them to mix residual PBST and methanol. After washing the embryos two more times with methanol, store them at minus 20 degrees Celsius for at least two hours up to several years. Using a microscope equipped for optical sectioning, capture images of immunostained embryos.

Immunofluorescent staining experiments with appropriate mRNA amounts and light exposure conditions showed that the pSmad levels were similar and non-injected in unexposed embryos, whereas injected light exposed embryos exhibited higher levels of Smad phosphorylation.